A known apparatus is described, for instance, in WO2004/011154. This document discloses a so-called continuous jet printer for generation of droplets from materials comprising fluids. With this printer, fluids can be printed. During the exit of the fluid through an outlet channel, a pressure regulating mechanism provides a disturbance of the fluid adjacent the outflow opening. This leads to the occurrence of a disturbance in the fluid jet flowing out of the outflow opening. This disturbance leads to a constriction of the jet which in turn leads to a breaking up of the jet into drops. This yields a continuous flow of egressive drops with a uniform distribution of properties such as dimensions of the drops. The actuator is provided as a vibrating bottom plate. However, due to the dimensioning of the bottom plate, higher frequencies are difficult to attain.